Holographic recording media comprising certain photosensitive .alpha.-diketones dissolved in polymeric precursors which are curable to form transparent polymers are known and disclosed in the copending Ross application identified hereinabove. Suitable polymeric hosts include acrylic resins and epoxy resins which are cured and hardened by adding various catalysts or curing agents to the polymeric precursors. These holographic recording media have excellent sensitivity, and are relatively easy and inexpensive to make, generally by dissolving the photosensitive compound in the polymeric precursor and curing the polymer.
The Bartolini et al. application identified above discloses that .alpha.-diketones capable of hydrogen atom abstraction in a cured acrylic polyester host will record holographic information which can be stored permanently in the recording media.
Certain .alpha.-diketones, such as 2,2'-furil, cannot be employed as the photosensitive material in the recording media known heretofore because they are not soluble in the polymer precursors to any practicable extent. Other photosensitive materials, particularly those which are not .alpha.-diketones, such as quinones or nitro compounds, cannot be employed with host polymers which require catalysts or curing agents. Reactions between these photosensitive compounds and the catalysts or curing agents may degrade or inactivate the photosensitive material or inhibit the curing process of the polymer. Thus a host material which is a good solvent for photosensitive materials and which does not require catalysts or other curing agents to harden it to a transparent solid, would be most desirable.